Roller cages for roller bearings



March 10, 1959 N. A. PALMGREN ROLLER CAGES FOR ROLLER BEARINGS OriginalFiled Aug. 23, 1955 2 Sheets-Sheet 1 March 10, 1959' N. A. PALMG'REN2,876,529 I R I ROLLER CAGES FOR ROLLER BEARINGS Original Filed Aug. 25,1955 I 2 Sheets- Sheet 2 wa P r01 MM 2,876,529 ROLLER CAGES FOR ROLLERBEARINGS Nils Arvid Palmgren, Goteborg,

Industries, Inc., Delaware Sweden, assignor to SKF Philadelphia, Pa., acorporation of 1 Claim. (Cl. 29-148.4)

This invention relates to roller beari cages of the one piece type, thathave window-like openings or pockets for the rollers separated by crossbars that permit radial insertion of rollers and provide for theirretention by means of protrusions into the pocket spaces.

The primary object of the invention is to provide a simple andeconomically practical method of producing cages of the aforesaid type.

A more specific object is to provide a method for production of cages ofthe stated type wherein the roller pockets and roller retaining elementsmay be formed by punching operation. 7

For several years roller bearing manufacturers have used cages made inone piece because: they possess greater strength than those assembledfrom two or more parts fastened together; they eliminate assemblyoperations; and, especially in the case of pressed metal cages, to whichthis invention most nearly applies, they provide for precise manufacturein large quantities at consequent low cost. The one-piece cage alsosimplifies assembly because the assembler may without complicationinsert the rollers radially and successively into the several pockets.

In order to keep the assembly of rollers, cage, and one race ring intactfor handling, prior designers have arranged to manipulate metal at someparts of the cross bars, as by prick punching the metal near the edgethereof or by the bending of tangs toward the rollers, so as to obstructthe pocket space after the rollers have been inserted. Such manipulationrequires time as well as skill in exercising proper control.

The invention contemplates production from a pressed metal cup or blank,and solely by punching operation, of a cage having a series ofwindow-like pockets and pocket-separating cross bars with protrusionswhich offer slight interference to radial entrance or exit of therollers. Precise control of the distance between protrusions in relationto roller diameter, combined with choice of material possessingsufiicient springing qualities, permits radial passing of the rollersbetween the protrusions, from whence they will not repass by their ownweight but only by force applied to the rollers. The cross bars yieldelastically and suffer no plastic deformation in this process, whencorrectly proportioned.

The drawings illustrate application of the cage of this invention to thewell-known double row spherical roller bearing, and in the drawings:

Figs. 1 and 2 show side and end views respectively of a finished cage;

Fig. 3 shows a fragmentary cross section cut by a plane approximatelyperpendicular to the axis of the cage and bisecting the pockets;

Fig. 4 is a fragmentary cross sectional view through one pocket on amedian radial plane containing the axis of the cage;

Fig. 5 is a fragmentary plan view showing one of the cross bars;

Fig. 6 is a sectional view on the line 6-6, Fig. 7;

United States Patent 0 Fig. 7 is a fragmentary plan view of the cage inan intermediate stage of formation;

Fig. 8 is an enlarged fragmentary view in perspective showing one of thecross bars;

Fig. 9 shows a pressed metal cup-shaped blank with which the process ofmanufacturing the cage begins;

Fig. 10 shows the cupped blank mounted on a face plate in position forpunching that portion of a pocket which conforms with the longitudinalprofile of a roller;

Fig. 11 shows in cross section one-half of a spherical roller bearingwith rollers in central operating position wherein the axes of therollers of each row intersect the bearing axis at a common point, saidbearing including cages in accordance with this invention;

Fig. 12 is a sectional view similar to Fig. 11 but taken through a crossbar of the cage, and Fig. 13 is a fragmentary sectional viewcorresponding to that of Fig. 4 but of a cage suitable for cylindricalrollers.

This invention provides a one-piece cage for spacing the rollers ofroller bearings, illustrated herein primarily for spherical rollerbearings but applicable as well to cylindrical roller bearings. Forspherical roller bearings it has a cup-like form with a series ofequally spaced window-like pockets which conform with the lengthwiseprofile of the rollers, except for short distances in the centralregions where protrusions project a little into the pocket spaces toobstruct slightly entrance or exit of rollers during assembly ordisassembly.

The cage comprises a ring portion 1, a series of pockets 2, and crossbars 3 between pockets having protrusions 4 and flat surfaces 5 whichform the side walls of the pockets.

These side walls clear the roller a few thousandths of an inch to allowfree rolling and can contact the roller from end to end only at one sidethereof at a time, as along dotted line 6 of Fig. 4. Fig. 3 shows aroller in its central operating position in the left-hand pocket,resting against the inner raceway indicated by are 7. Obviouslyprotrusions 4 will prevent the roller from moving radially outwardlywithout application of force. The invention provides for movementoutwardly for disassembly and for movement inwardly for assembly, bychoosing for the cage a material having spring-like qualities and bycarefully controlling the distance 8 between two parallel flat surfaces9, 9a at the outer extremities of the confronting protrusions 4 adjacentto the outer periphery of the cage. Such cage material may consist forexample of heat treated steel, non-ferrous metal or plastic. Theinvention also provides a cross bar of such width with respect to theroller diameter, that it will spring circumq ferentially of the cagepurely by reason of its elasticity to allow passage of each roller inand out of its pocketso that no permanent (that is plastic) deformationat the surfaces will take place. Such organization permits innumerablerepetition of roller passage without injury to the cage.

Obviously if the surfaces 9, 9a should continue inwardly parallel withthe side walls 5, they would interfere with the rollers assuming theirnormal positions in the pockets. The invention, therefore, provides forcutting off the said protrusions on an angle which will clear therollers. Lines 10, 10a in Fig. 3 are the traces of the surfaces, and thenumeral 11 in Fig. 4 indicates a face thereof.

The invention also comprises the method of manufacturing this cage inquantity within precisely controlled dimensions. The novelty of methodresides in the formation of the previously described essential surfacesof the roller retaining protrusions by punching operations.

The process begins with the pressed metal cup of Figs. 9 and 10 which Imount as shown schematically on a face plate 12 by means of three pins13, 13, 13 passing through-threeholes 14,14, 14 in the bottom of cup 15.I later punch out and discard this bottom portion at circle 16. The face17 of-=the plate must tilt from the vertical by the angle A of Fig. 10which corresponds with the angle A of Fig. ll between the center planeof symmetry 18 of the bearing for which the cage is designed, I

and the line 19 connecting the bearing center '20 with the center 21 ofany of the rollers when the latter is in the central operation positionin its pocket as shown in Fig. 3. Line 19 lies perpendicular to the axisof the roller at its center when the roller is in the aforesaid centraloperating position, in which positions the axes of all the rollers ineach row intersect at a common point of the "bearing axis.

The punch of which'two sets are used in the process, act verticallydownwardly along the center line 18b, Fig. 10. In the case of the punchcutting the walls 5, the line 18b corresponds with the line 19 whichconnects the bearing center 20 with the geometric center 21'of a roller,and in the case of the punch cutting the surfaces 10 and 10a, the line18b corresponds to line 19a, see Fig. 12, which connects the bearingcenter with .the geometric center of one of the cross bars 3.

The first-named punch has the outline of the pocket 'Zshown most clearlyat the center of Fig. 1. This punch "cuts out a slightly larger holethan that which would represent the profile of the roller except in thecentral regions of cross bars, where it leaves metal for the other punchto cut away to provide the previously explained angular reliefs 10 and10a. In passing through the cup material, the first-named or outliningpunch will produce the fiat walls between which the roller may moveradially without touching but with which the roller maymake contact atone side or the other for guidance. In the event that the second-namedpunch performs its operation in advance of the first-named punch, asillustrated in Figs. 6 and 7, the first-named punch may at the same timeit forms the walls 5 and end walls 5a of the pocket, cut thetwo narrowparallel flat surfaces 9 and 9a on each side of the pocket.

After the outlining punch withdraws from the punched pocket, the faceplate by means of familiar devices, will rotate the cup blank acircumferential distance equal to that between pocket centers, asindicated at 25, 25a in Fig. 2 so that said punch may cut out the nextand, successively, subsequent pockets. This punch leaves material at thecentral regions of the cross bars and within the pocket space as shownin the pocket 2 of Fig. at 23, 23a. This material will have been eitherpreviously shaped by the relief punch to the undercut form of theprotrusions 4, 4 or must subsequently be so shaped by said punch topermit the roller to assume its operating position in the pocket.

The second-named or relief punch having its cutting edges in the form ofthe two rectangles 27, 27a of Fig. 7, acting vertically on a center linecorresponding to 19a aspreviously described, and wide enough to reachfrom the left side of one pocket to the right side and relatively remoteside of an adjoining pocket, see Fig. 7, will cut parallel faces 10 and10a simultaneously, said punch having a recess affording clearance forthe cross bar between these pockets. By successively indexing the faceplate 12 and the cage blank through angle equal to that containedbetween the geometric centers of two adjoining cross bars, the undercutfaces of all of the protrusions 4 may be cutby the punch, two at a time.

Obviously the two punches must act independently along line 19 of Fig.11 or theline 19a of Fig. 3, respectively. As indicated above the orderin which the punches are made to operate on the blank is a matter ofchoice.

It will be noted that the punches move as though from the bearing center20, radially outwardly along line 19 of Fig. 11, or 19a of Fig. 3 aseach pocket or cross bar comes into position. The face plate indexes theblank from pocket center to pocket center for the outlining punch, andfrom cross bar center to cross bar center for the relief punch.

The cage of this invention will suit cylindrical rollers --as well asthose with curved profile as just described, see Fig. 13. In this casethe outlines of the pockets become rectangles, angle -A becomes zero,and the axis c of the rollers parallel .to the bearing axis.

This application is a division of my co-pending application SerialNumber 430,l39, filed August 23, 1955, as a continuation of applicationSerial Number 141,875, 'now abandoned, of the same inventor filedFebruary 2, 1950, application Serial Number 530,139 having now maturedinto Patent Number 2,805,108 dated September 3, 1957.

I claim:

The method of manufacturing annular cages for roller bearings havinga-circumferential series of radially opening window-like pockets for therollers separated by cross bars together with roller-retainingprotrusions projecting into the pockets from the central portions ofsaid bars, said protrusions having pocket-confronting faces inclined toand diverging outwardly of the cage from the faces of the cross barsfrom which they respectively project, said method consisting of a firstseries of punching operations progressing around the cage annulus, eachsaid operation forming two separate and relatively remote aperturesrespectively shaping the inclined faces of two of said protrusions lyingrespectively at the relatively remote sides of two of said pockets, andsaid operations collectively forming in successive pairs the inclinedfaces of all of said protrusions, and a second series of punchingoperations progressing around the cage annulus, and each forming the twoend portions of an individual pocket including the pocket confrontingside faces of the proximate cross bars at the opposite sides of the saidprotrusions.

References Cited in the fileof this patent UNITED STATES PATENTS1,712,076 Hughes May '7. v1929 2,327,237 Baden Aug. 17,1943 2,756,518Lovell Oct. 9, 1956 UNITED STATES PATENT OFFICE CERTIFICATE()FJCORRECTION Patent No, 2,876,529 Marsh 10, 1959 Nils Arvid PalmgrenColumn 3, line 9, for "operation" read operating column 4, line 25, for"Serial Number 430,(l39" read Serial Number 530,139 -a Signed and sealedthis 14th day of July 1959;,

(SEAL) Attest: KARL H, AXLINE ROBERT C. WATSON Attesting OflicerCommissioner of Patents

